I had formatted the T7 with Mac OS Extended
I originally tried opening from within Photos, when it was the System Photo Library, as usual but no go.
Then I tried clicking on the file directly, which opened Photos and right into an error window
Since the Sequoia update clearly broke something the Photos app it would crash immediately, no option to find the folder.
So I copied the photos file to the internal drive and it works fine in that case.
Trying to re-open the same file, from the Photos window, from the external drive, just brings up an error message.